Most users today connect their computer terminals to the Internet over a telephone line through their Local Exchange Carrier (LEC) to an Internet Access Provider (IAP), which provides access to the Internet and connection to a plethora of various Internet Service Providers (ISPs) that offer information and interactive services. Modems operating at rates such as 14.4 kbps or 28.8 kbps are available to connect a user's terminal to the telephone line for transport of data to and from the IAP, and thus the Internet and the ISPs.
As more and more information and services have been made available over the World Wide Web, people are spending more and more time "surfing the Net", and thus tying up their telephone line. If an Internet user has only a single telephone line, callers trying to reach such a user may not find it uncommon to get a busy signal for hours on end. Call Waiting services available from local telephone companies, which allow a subscriber to answer an incoming call from a second party while conversing with a first party cannot be used while a user is engaged in an Internet call since the user is not made aware of the incoming call and has no ability to switch his or her connection to the Internet to take the telephone call. In fact, a service such as Call Waiting must be disabled by the user prior to placing an Internet call to prevent a Call Waiting alerting tone from causing the user's modem to drop the telephone connection to the IAP.